1. Field of the Invention
The present invention relates to a nitride semiconductor device including a P-type electrode and a method of manufacturing the same.
2. Description of the Background Art
In a conventional nitride semiconductor device, palladium (Pd) is used as a material of a P-type electrode formed on a P-type contact layer (for example, “Temperature-dependent contact resistivity of the nonalloyed ohmic contacts to p-GaN”, Joon Seop Kwak et al., JOURNAL OF APPLIED PHYSICS, VOLUME 95, NUMBER 10, May 15, 2004, PP. 5917-5919).
When a laser diode, for example, is manufactured using the nitride semiconductor device as described above, if a P-type contact resistance is not sufficiently low, an operation voltage for operating the laser diode is increased and properties of the laser diode vary due to heat produced during operation. As a result, it is difficult to manufacture a laser diode which can attain stable operation and output within a specified temperature range. Therefore, a nitride semiconductor device having a decreased contact resistance between a P-type contact layer and a P-type electrode is required.